Derivatives of aminoalkanoic acids

ABSTRACT

(3,4,5-trialkoxy benzoyl) amino alkanoic acids and their pharmaceutically-acceptable salts for prophylaxis and treatment of cardiac disorders.

United States Patent Garzia 1 Apr. 10, 1973 DERIVATIVES OF AMINOALKANOIC[56] References Cited ACIDS UNITED STATES PATENTS Inventor: Aldo Gama,Lodi Italy 3,489,793 1/1970 Bertelli ..260/5l9 [73] Assignee: IstitutoChemioterapico Italiano Primary Examiner-Lorraine A. Weinberger S.p.A.,Milan, Italy Assistant Examiner-L. Arnold Thaxton AttorneyMorton,Bernard, Brown, Roberts & [22] June 1970 Sutherland, Eugene L. Bernard,John W. Behringer, [21] Appl. No.: 50,331 Martin J. Brown, James N.Dresser, W. Brown Morton, Jr., John T. Roberts and Malcolm L. Sutherland[52] US. Cl. ..260/519, 260/404, tat/$31189, [57] ABSTRACT 51 Int. Cl..C07c 103/30 y y amino alkanoic acids and 5s Field of Search ..260/519,404 their phamaceutically-acceptable Salts for P p y and treatment ofcardiac disorders.

6 Claims, No Drawings 1 DERIVATIVES OF AMINOALKANOIC ACIDS BACKGROUND OFTHE INVENTION This invention relates to a method of prophylaxis andtreatment of cardiac disorders. In a particular aspect, it relates to amethod of treating ischemic cardiopathy prior to or following a cardiacinfarction, disorders of rhythm, and disorders of stimulus transmissionby the administration of an aminoalkanoic acid derivative.

The prevention and treatment of cardiac disorders, such as ischemia,thrombosis, cardiac infarction and disorders of rhythm and stimulustransmission, is a serious problem. Many studies have been conducted inan effort to ascertain the underlying causes and to develop a suitablemethod of preventing or treating these serious problems, particularlycardiac insufficiency and cardiac infarction. The pharmacologicalmethods which have been proposed for preventing cardiac infarctioninclude lowering of blood cholesterol levels, relaxation of the arteriesand administration of anticoagulants. Ventricular fibrillation is ahighly dangerous condition which is treated by electric shockadministered to the hear muscle, and other rhythm and transmissiondisorders respond to installation of the pacemaker device.

While the use of these methods has greatly improved the prognosis ofcardiac patients, the problem of cardiac disorders generally stillremains a severe one and in particular the problems caused by infarctionare still grave.

SUMMARY OF THE INVENTION It is an object of this invention to provide amethod of prophylaxis and treatment of cardiac disorders.

It is another object of this invention to provide novel pharmaceuticalcompositions suitable for the prophylaxis and treatment of the cardiacdisorders.

Another object of this invention is to provide a method of prophylaxisand prevention of ischemic cardiopathy, cardiac infarction and disordersof rhythm and stimulus transmission. by the administration of thederivatives of aminoalkanoic acids.

' Other objects of this invention will be readily apparent to thoseskilled in the art from the disclosure herein.

It has been discovered that administration of compounds corresponding tothe following formula where each of R, R and R is methyl, ethyl orpropyl, A is a saturated aliphatic hydrocarbon radical containing threeto eight carbon atoms, and the carboxylic acid group is linked to A at aposition other than terminal, or their phannaceutically-acceptablesalts, is effective in the prophylaxis and treatment of cardiacdisorders such as cardiac ischemia and infarction, disorders of rhythmand disorders of stimulus transmission. The compound is administered ata dosage of 2-8grams per day per average 60-70 kg. individual. Whenadministration is by intravenous or intraperitoneal injection, soluble,pharmaceutically acceptable salts 200 the compounds of this inventionare preferred.

DETAILED DISCUSSION The compounds of the present invention are preparedby reacting the appropriate 3,4,5-trialkoxy benzoyl chloride with thecorresponding amino-alkanoic acid at a temperature of about 5 to +5C.According to the process of this invention, the free amino acid isslurried in about an equal weight of water and is neutralized withsodium hydroxide solution. (about 30 percent by weight). Excess sodiumhydroxide is added to promote the reaction. The mixture is chilled towithin 5C to +5C, and the tri-substituted benzoyl chloride is graduallyadded with agitation, maintaining the temperature at below 5C. The moleratio of amino acid to the acid chloride is generally about i 1.5:1. Theresulting solution is stirred for from two to four days and when thereaction is complete can be treated with char to decolorize it. It isthen neutralized with dilute I-ICl or H to about a pH of 3 or a Congored indicator endpoint. The resulting precipitate is separated, e.g. byfiltration or centrifugation, washed with water, dried, thenrecrystallized from water or ethanol, separated by filtration,centrifugation or decantation and dried.

According to the method of the present invention, compoundscorresponding to the formula given. hereinbefore are administered forthe treatment of cardiac ischemia, either prior to or following acardiac infarction, disorders of the rhythm whether related to theinfarction or not, and disorders of stimulus transmission.Administration of these compounds is an effective prophylaxis in casesof an impending cardiac infarction and an effective treatment afterinfarction has occurred. According to one embodiment of the presentinvention, the method is employed in veterinary medicine, principally inthe treatment of household pets, especially dogs, where cardiac problemsare frequently encountered.

Cardiac infarction frequently occurs without prior symptoms or beforethe patient has sought treatment for the relief of symptoms Howeverphysicians are frequently able to detect symptoms of an approachingcrisis and the administration of the compounds of this invention can bestarted promptly to obtain prophylactic effects.

The products of the present invention are of a loworder of toxicity andno side effects are observed in clinical trials. Pharmacological studiesindicate that the principal effect of the compounds of the invention ison the heart. The only observed effect on the circulatory system is anincrease in the static blood pressure with no significant change in meanarterial pressure.

The dosage in which the compounds of the present invention can be givencan vary widely within rather broad limits. Good results have beenobtained with as little as 25 mg/kg/day and as much as 500 mg/kg/day. inhuman clinical cases, all of the disorders cited above generally respondto a dosage of 2-8g per day per person, preferably about 6g per day.This dosage is intended for an average 60-70 kg individual equivalent toa dosage generally within the range of about 25-200 mg/kg/day. A dosagein the range of about 40-100 mg/kg/day is preferred. The treatment canconsist of a single daily dose, or the above dosages can be givenfractionally at periodic intervals. A single daily dose is generallypreferred for a treatment of cardiac infarction and associated disordersbut for prophylaxis,

smaller periodic doses, e.g. a 1000 mg. dose, six times daily, ispreferred.

Administration of the compounds of this invention can be oral,subcutaneous, intravenous or intraperitoneal. When the compounds of thepresent invention are by subcutaneous, intraperitoneal or intravenousinjection, they are administered as their water-soluble neutral salts.Any soluble, pharmaceutically-acceptable salt is suitable and the sodiumand potassium salts are preferred. The sodium salt is particularlypreferred. For oral administration the compounds are preferablyadministered as the free acids but they can also bepharmaceutically-acceptable salts, e.g. as the ammonium, sodium,potassium, magnesium or calcium salt. According to one suitable method,the free acids can be administered mixed with a molar equivalent ofsodium or potassium bicarbonate. in the examples, the compounds wereadministered intraperitoneally as the sodium salt because of its ease ofhandling as an aqueous solution, but the weights given are for the freeacid. When administered orally, the compounds are convenientlyadministered as tablets containing 500 mg with a suitable binder, manyof which are known.

Suitable tablets for human or animal use can conveniently be preparedcontaining 50-500 mg of the compounds of the present invention, eitheras the free acid or as a pharmaceutically-acceptable salt thereof.Tablets containing as little as 50 mg are suitable for oraladministration, especially for infants and small children, and inveterinary medicine, for small animals. Tablets containing less than 50mg can be prepared, and in special cases may be useful, but generally adose smaller than 50 mg is too small to be practical because in theaverage patient the number of tablets required per day would beexcessively high for convenience. Tablets containing more than 500 mgcan also be prepared, but large tablets are difficult for most patientsto swallow.

EXAMPLE 1 To a 500 cc flask in an ice bath is added 18.5 grams ofL-isoleucine (0.14 mole) and 40 cc of water. A solution of 10 grams ofsodium hydroxide in 40 cc of water is added to solubilize the acid andan additional 9 grams of sodium hydroxide in 30 cc of water is added.Then at l0C are added 27 grams of 3,4,5-trimethoxybenzoyl chloride inabout 30 minutes, and 75 cc of water. After one night at roomtemperature the reaction mixture is decolorized with charcoal andacidified with 20 percent hydrochloric acid to the end-point 1 shown byCongo Red. The sticky precipitate is washed by decantation, and morewater is added. After standing two days at room temperature, the solidis ground in a mortar under fresh water. This gives a white crudeproduct.

Five grams of the crude product was recrystallized from 600-700 cc ofboiling water to give 3 grams of product with a melting point ofl55-157C and a purity of 98.81 percent. The remainder of the crudeproduct was recrystallized from boiling water to give 21.9 grams.

The product is N-( 3,4,5-trimethoxybenzoyl)-L- isoleucine having thestructure 0 H O i O OH omo-Q-o 0NH(.HCHGH2CH3 o H; o (11H;

' EXAMPLE 2 DL-Norvaline l 1.7 grams (0.1 mole) water 8 grams Sodiumhydroxide (10%) 200 milliliters Sodium carbonate 16 grams The abovemixture is cooled to 0C. and 23.5 grams of 3,4,5-trimethoxybenzoylchloride and 150 cc of diethyl ether are added slowly at O5 C. Themixture is stirred at 0C. for one hour then allowed to warm to roomtemperature overnight. The ether is removed and the aqueous layer isacidified to Congo Red end-point with dilute hydrochloric acid afteradding 600 ml. of water. Filtration followed by washing with cold watergives 25 grams of crude product.

Ten grams of crude product was dissolved in 50 cc of chloroform andmixed with 45 cc of ligroin to precipitate 9.9 grams of purified productmelting at l64-l65 C. and assaying 99.73 percent pure.

The product is N-(3,4,5-trimethoxybenzoyl)-DL- norvaline -DL-n0rvalinehaving the structure COOH EXAMPLE 3 To 40cc of water is added 18.5 gramsof L-leucine. This is neutralized with 10 percent sodium hydroxide (40cc) and then an additional 9 grams of sodium hydroxide in 30 cc of wateris added. The solution is cooled to 0-5 C and 27 grams of3,4,5-trimethoxybenzoyl chloride and cc of water are added at 05 C in 30minutes. After one night at room temperature, the reaction mixture isacidified to Congo Red endpoint but it does not crystallize at once.After about 3 days it is crystallized by grinding with ice water andligroin while cooling in an ice bath. The yield of crude product is 17.5grams and the melting point is 7375 C.

The product is N- (3,4,5-trimethoxybenzoyl) -L-leucine having thestructure COOH CIT;

EXAMPLE 4 The effect of the compound prefered according to the procedureof Example I on the heart is determined in rats by intravenous injectionof 1 unit per kilogram of vasopressin (Pitressin, marketed by Parke,Davis Co.), an antidiuretic pituitary hormone. As is known, theadministration of vasopressin results in variations of the voltage andthe morphology, or shape, of the T- wave. It also causes arrhythmia andproduces ischemia of the myocardium. It is determined that theseelectrocardiographic alterations normally produced by the administrationof Pitressin are prevented by the administration of the compound ofExample 1.

EXAMPLE 5 The effects of the compound of Example 1 is determined onchloroform-epinephrine induced arrhythmias in rats. In the procedureemployed, the rats are anaesthetized with urethane. Chloroforrn isadministered for one minute by inhalation and then 100 micrograms/kg ofepinephrine hydrochloride is ad ministered intravenously.Electr'ocardiograms are taken and the extent of the arrhythmia in termsof number of beats per minute is determined. The effect of the compoundof Example 1 is substantially to reduce the extent of the arrhythmiawhen administered intraperitoneally in the amount of 700 mg/kg.

EXAMPLE 6 (3,4,5-Triethoxybenzoyl)-a-aminoisovaleric acid is prepared inaccordance with the procedure of Example 1 The resulting compound istested for anti-Pitressin activity in rats as described in Example 4 andsimilar results are obtained.

EXAMPLE 7 (3,4,5 Tripropoxylbenioyl)-L leucine is prepared in accordancewith the procedure of Example 1. The resulting compound is tested foranti-Pitressin activity in rats as described in Example 4 and similarresults are obtained.

EXAMPLE 8 (3,4-Dipropoxy-S-ethoxybenzoyl)-L-isoleucine is prepared inaccordance with the procedure of Example 1. The resulting compound istested for anti-Fit ressin activity as described in Example 4 andsimilar results are obtained.

EXAMPLE 9 A pharmaceutical composition in tablet form was prepared bymixing 500 mg of the compound of Example l with 50 mg of corn starch and50 mg of sucrose. This mixture was compressed in a tableting machine tomake a durable tablet. It is suitable for oral administration to humansor other animals suffering from cardiac disorders. It is particularlysuitable for prophylaxis of a suspected impending coronary occlusionresulting in an infarction.

The above examples are representative. For example, the 3,4,5-trialkoxybenzoic acids are well known to the art. See, for example, US. Pats.Nos. 3,234,276; 3,364,249 and 3,485,865. Amino acids other than thoseutilized in the examples can be prepared by means known to the art. Forexample, thefollowing amino acids can be utilized:

2-amino- Z-ethyl butyric acid 2-amino- Z-methyl hexanoic acid 2-ammo-2,4-d1methylpentano1c acid alpha methyl norvaline 3-methyl- 2-amino-2-n-propyl butyric acid l-aminol-n-propyl pentanoic acid 2-amino-2-n-butyl hexanoic acid 2-amino- 2-n-butyl- 4-methyl pentanoic acid Iclaim:

1. A compound represented by the formula wherein each of R R and R ismethyl, ethyl or propyl, A is a saturated aliphatic hydrocarbon radicalcontaining three to eight carbon atoms and the carboxylic acid group islinked to A at a position other than terminal, and pharmaceuticallyacceptable salts thereof.

2. The compound of claim 1 where R R and R are methyl and (A )COOI-l is3. The compound of claim 1 where R R and R are methyl and (A)COOH is 4.The compound of claim 1 where R R2 and R are methyl and (A)COOH is 5.The cqrppgnmd of claim 1 wherein the pharmaceutically acceptable saltsare the s odiumoi' potassium salts of the compound.

6. A compound represented by the formula wherein each of R R and R ismethyl, ethyl or propyl, A is a saturated aliphatic hydrocarbon radicalcontaining three to eight carbon atoms and the carboxylic acid group islinked to A at a position other than terminal.

UNITED STATES FATE QFMQE CERTHEQATE G REQ'HQN Patent 5, 3,726,913 DatedMay 7, 1973 lnvehtor(s) ALDO GABZIA It is certified that error appearsin the above-identified patent and that said Letters Patent are herebycorrected 'as shownibelow:

Column 1, line 23, the word "hear" should read -'heart-.

Column line lii henum i be deleted and of inserted t hefefoie Column 2,line 15, the numerals "1 1.5:1" should read -lln5:l-.

sighed and sealed this 26th day of March 197M...

(SEAL) Attest:

EDWARD MFLETGHER,JRa. 0., MARSHALL DANN Attesting Officer Commissionerof Patents USCOMM-DC 60376-1 69 ORM PO-105O (10-69) u.s. GOVERNMENTPRINTING OFFICE 1959 o-sss-aan

2. The compound of claim 1 where R1, R2 and R3 are methyl and (A)COOH is3. The compound of claim 1 where R1, R2 and R3 are methyl and (A)COOH is4. The compound of claim 1 where R1, R2 and R3 are methyl and (A)COOH is5. The compound of claim 1 wherein the pharmaceutically acceptable saltsare the sodium or potassium salts of the compound.
 6. A compoundrepresented by the formula wherein each of R1, R2, and R3 is methyl,ethyl or propyl, A is a saturated aliphatic hydrocarbon radicalcontaining three to eight carbon atoms and the carboxylic acid group islinked to A at a position other than terminal.